Between a third and half (43%) of the UK population--roughly 28 million adults--lives with chronic pain, finds an analysis of the available evidence, published in the online journal BMJ Open.
This proportion is likely to rise as the population ages, warn the researchers, who add that chronic pain is a major cause of disability and distress among those affected by it.
There is no consensus on the proportion of people living with long term pain in the UK, and in a bid to try and gain an accurate picture, the researchers trawled relevant databases to find research on different types of pain, published after 1990.
Their search included studies on population based estimates of chronic pain--defined as lasting more than 3 months--chronic widespread pain, fibromyalgia (a rheumatic condition characterised by muscular or musculoskeletal pain), and chronic neuropathic pain (pain caused by nerve signalling problems).
From among 1737 relevant articles, 19 studies, involving just under 140,000 adults, were deemed suitable for inclusion in the final analysis.
They pooled the study data to arrive at an estimate of the prevalence of chronic pain, overall, and chronic widespread pain. Summary estimates were also drawn up for moderate to severely disabling chronic pain, fibromyalgia, and chronic neuropathic pain among UK adults.
Based on seven studies, the researchers worked out that the prevalence of chronic pain ranged from 35% to 51% of the adult population, with the prevalence of moderate to severely disabling chronic pain (based on four studies), ranging from 10% to 14%--equivalent to around 8 million people.
Pooling of the data showed that 43% of the population experience chronic pain, and 14% of UK adults live with chronic widespread pain. The summarised data also showed that 8% of UK adults experience chronic neuropathic pain, and 5.5% live with fibromyalgia.
Twelve of the studies categorised the prevalence of pain by age group, and unsurprisingly, these showed that older people were more likely to live with pain over the long term.
Among 18-25 year olds, the prevalence was 14%, although it may be as high as 30% among 18-39 year olds, the analysis indicates--a sizeable chunk of the working population, say the researchers.
Among those aged 75 and above, the prevalence was almost two thirds (62%), suggesting that if current trends continue, the burden of chronic pain may increase further still as the population ages, say the researchers.
Women were more likely than men to be affected by chronic pain, irrespective of age or pain type.
The researchers point out that the included studies varied considerably, and that not all of them were of high quality, so making it difficult to draw firm conclusions.
The studies showed gradually increasing prevalence of chronic pain over time, from 1990. And the researchers estimate that the prevalence of chronic pain in the UK is now around 43%, equating to around 28 million people, based on population stats for 2013.
"Such prevalence data does not itself define need for care or targets for prevention, but reliable information on prevalence will help to drive public health and healthcare policymakers' prioritisation of this important cause of distress and disability in the general population," they conclude.